1. Field of the Invention
The present invention relates to apparatus used for ultrasonic imaging. More particularly, it relates to apparatus for simultaneous imaging in both longitudinal and transverse views. More specifically, it relates to apparatus for imaging for purposes of medical diagnosis and treatment, especially for diagnosis and treatment of organs such as the prostate.
2. Prior Art
There are various situations in which it is necessary to do ultrasonic imaging to assist in medical diagnosis and treatment. For example, prostate cancer is one of the most common cancers found in men. Treatment options include “watchful waiting”, hormonal therapy, brachytherapy, or surgery. Three types of surgery are used. The classical “open” procedure, radical prostetectomy, and the newly developed laproscopic and cryosurgery procedures. All procedures have risks. Both the open procedures and the laproscopic procedures have significant risks of causing impotence and incontinence. With both brachytherapy, and cryosurgery the prostate is left in vivo, and therefore the risk of complications is much lower, and the recovery time is quicker.
In brachytherapy, trains of seeds are implanted in rows in the prostate. Cryosurgery is done in a similar fashion, except that cooling needles are inserted in eight to twelve locations in the prostate. Cold gases are circulated through the needles, and the prostate is monitored by ultrasound imaging for the formation of ice balls, which indicates proper operation of the device. Both of these procedures may be preformed under local anesthetic.
As illustrated in FIG. 1, ultrasound guidance is used in order to properly locate the needle holding the seeds for brachytherapy or the needles for cryosurgery. In FIG. 1, those skilled in the art will recognize the following bladder B, prostate P, urethra U, rectum R, perianal wall Pe, operator 10, ultrasonic probe 12, needle grid block 14, needle 16, needle core 18, and seeds 20.
As illustrated in FIG. 2, in the prior art, the typical bi-plane ultrasonic probe 22 used has a linear transducer array 24 to image the sagital or longitudinal view, and a micro-convex curved array 26 for the transverse view. The linear array is usually 50 mm long, and is not long enough to visualize the entire prostate in many patients.
As illustrated in FIG. 3, the micro-convex array 26 is at the end of the probe, and its imaging plane 28 does not intersect the linear array's imaging plane 30. This causes the operator to have to constantly move the probe to different positions along the rectum during the procedure. This is time consuming, and more importantly, causes the prostate to move, leading to more uncertainty as to where the seeds are being placed.